Chapter 5. Relational and Object-Relational Database Concepts


The relational model was originally developed by E. F. Codd in the '70s. The relational concept is a simple but strict concept and describes the treatment of two-dimensional data with the help of tables.

PostgreSQL can be used as a relational database. However, PostgreSQL is also capable of handling object and hierarchical data. The object-oriented paradigm differs significantly from the relational concept, and with the help of PostgreSQL, it is possible to utilize both concepts in order to build even more powerful applications. Especially in combination with object-oriented languages, PostgreSQL's concepts can be a significant advantage and will help you to build databases that are easier to understand.

According to the relational concept, two ways of looking at data are defined: The organization of data into relational tables is known as the logical view of the database. The counterpart of the logic view is the internal view of the data. Depending on the kind of data your database stores, the logical and internal view of the data can differ. When working with SQL, the user is accessing data via a predefined interface, which in the case of PostgreSQL, is SQL. The way data is stored by PostgreSQL internally need not affect the user. The idea is to have a standard interface for interacting with the data it is not necessary to think about how the data is stored by the database internally.

However, the logic structure of your database is one of the most important things when storing data in a database. To store data in a flexible and efficient way, normalization has to be done.



PHP and PostgreSQL. Advanced Web Programming2002
PHP and PostgreSQL. Advanced Web Programming2002
ISBN: N/A
EAN: N/A
Year: 2004
Pages: 201

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